use strict;
use warnings;

my $string = "ASBSDEC 34 GADVVEEVEETTE 56 IOEOREAK GKJEOG EFEAF 1090 DAFFEE 376";

my $max;  # This is undefined until set
while ($string =~ /(\d+)/g) {
    if (!defined($max) or $max < $1) {
        $max = $1;
    }
}

print "Max value is $max\n";

##</code><code>##

use strict;
use warnings;

my $string = "ASBSDEC 34 GADVVEEVEETTE 56 IOEOREAK GKJEOG EFEAF 1090 DAFFEE 376";
my $max = max_val($string);
print "Max value is $max\n";


sub max_val {
    my $str = shift;
    my $max;
    while ($string =~ /(\d+)/g) {
        if (!defined($max) or $max < $1) {
            $max = $1;
        }
    }
    return $max;        # This will be undefined if no integer found
}